CVE-2026-110675 Cpanel::JSON::XS versions from 4.33 before 4.80 for Perl accept malformed UTF-8 in bare hash keys under allow_barekey in decode_hv.
Attackers can cause application crashes by sending malformed UTF-8 in bare JSON keys when specific decoding options are enabled.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-110675?
CVE-2026-110675 is a high-severity denial of service vulnerability, published on 19 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
Cpanel::JSON::XS versions from 4.33 before 4.80 for Perl accept malformed UTF-8 in bare hash keys under allow_barekey in decode_hv.
With utf8 and allow_barekey, which relaxed enables, a quoted key is validated as UTF-8 but a bare key's bytes are stored as a UTF-8 flagged string without any check. Malformed UTF-8, control bytes and backslashes reach the decoded hash, while malformed UTF-8 and control bytes in a quoted key or a value are rejected.
Later operations on the key, including lc, uc or encoding the hash again, die with a malformed UTF-8 error.
Weakness: CWE-1286
Which versions are affected by CVE-2026-110675?
How do I fix CVE-2026-110675?
Upgrade to a fixed version.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-110675 being exploited?
There is no known exploitation of CVE-2026-110675 in the wild and no public exploit code.
Sources
Also known as AZL-109839, DEBIAN-CVE-2026-110675, GHSA-9hvc-g7pw-p4j7, UBUNTU-CVE-2026-110675.